122 INBREEDING AND OUTBREEDING 



there has been no exception, the several inbred lines 

 originating from the same variety have become more or 

 less strikingly differentiated in morphological characters. 

 Some of the differences which characterize the several 

 inbred strains in various combinations are as follows : 



Colored and colorless pericarps, cobs, silks and glumes. 

 Profusely branched tassels and scantily branched or unbranched 



tassels. 

 Long ears and short ears. 

 Round cobs and flat cob®. 

 Narrow silks and broad silks. 

 Ears with various numbers of rows. 

 Ears with straight rows and ears with irregular rows. 

 Ears with large seeds and ears with small seeds. 

 Ears high on the stalk and ears low on the stalk. 

 Stalks with many tillers and stalks with few tillers. 

 Leaves with straight margin and leaves with wavy margin. 



Many other character differences governed by definite 

 inherited factors have been observed, but these may serve 

 as illustrations. 



Along with these normal differences a number of 

 characters have appeared which might well be called mon- 

 strosities, using the term not because of any abnormality 

 in the method of their inheritance, but because they are 

 not fitted to struggle for place either in agriculture or in 

 nature. A common occurrence is the isolation of dwarf 

 plants which are rarely capable of producing seed from 

 their own pollen. Plants manifesting various degrees of 

 chlorophyll deficiency are also frequently found. This 

 may show in the form of an entire lack of chlorophyll, as 

 seen in pure albino plants which live only until the supply 

 of food in the seed is exhausted; or, it may appear as a 

 yellowish green, the plants struggling through to seed 



